How do I upload a CSV file with my business tax return in TNTAP? You can find instructions on how to upload the CSV file and the CSV file format on our website here. March 19, 2019 14:36 Related articles TNTAP: Filing a Business Tax Return How do I file business tax online? TNTAP: Filing a Sales Tax Return How do contractors deduct payments made to subcontractors on their business tax return? How do I get an automatic F&E extension?